Physics

Problem

Consider two solid spheres

P

and

Q

each of density

8 \text{ gm cm}^{-3}

and diameter

1 \text{ cm}

and

0.5 \text{ cm}

, respectively. Sphere

P

is dropped into a liquid of density

0.8 \text{ gm cm}^{-3}

and viscosity

\eta = 3

poiseuille. Sphere

Q

is dropped into a liquid of density

1.6 \text{ gm cm}^{-3}

and viscosity

\eta = 2

poiseuille. The ratio of the terminal velocities of

P

and

Q

is _____.